The Journal of Neuroscience, July 1, 2000, 20(13):4798-4808
Ultrastructural Localization of Nitrotyrosine within the
Caudate-Putamen Nucleus and the Globus Pallidus of Normal Rat Brain
Elizabeth A.
Bolan1,
K.
Noelle
Gracy2,
June
Chan2,
Rosario R.
Trifiletti3, and
Virginia M.
Pickel3
Departments of 1 Pharmacology, 2 Neurology
and Neuroscience, and 3 Pediatric Neurology, Weill Medical
College of Cornell University, New York, New York 10021
Nitration of protein tyrosine residues by nitric oxide (NO)-derived
reactive species results in the production of stable nitrotyrosine (NT)
moieties that are immunochemically detectable in many regions of normal
brain and enriched in those areas containing constitutive nitric oxide
synthase (cNOS). These include the caudate-putamen nucleus (CPN) and
the globus pallidus, which receives major inhibitory input from the
CPN. To determine the functional sites for NT production in these
critical motor nuclei, we examined the electron microscopic immunocytochemical localization of NT and cNOS in rat brain. In the
CPN, NT was localized to the somata and dendrites of cNOS-containing interneurons and spiny neurons, some of which received input from cNOS-labeled terminals. The NT immunoreactivity was most prevalent on
outer mitochondrial membranes and nearby segments of the plasma membranes in dendrites and within asymmetric synapses on dendritic spines. In the CPN and globus pallidus, there was also a prominent labeling of NT in astrocytic processes, small axons, and tubulovesicles and/or synaptic vesicles in axon terminals. These terminals formed mainly asymmetric synapses in the CPN and inhibitory-type synapses in
the globus pallidus where they often apposed cNOS-containing terminals
that also formed asymmetric, excitatory-type synapses. Our results
suggest that NT is generated by mechanisms requiring the dual actions
of excitatory transmitters and NO derived either from interneurons in
the CPN or from excitatory afferents in the globus pallidus. The
findings also implicate NT in the physiological actions of NO within
the striatal circuitry and, particularly, in striatopallidal neurons
severely affected in Huntington's disease.
Key words:
nitric oxide synthase; nitric oxide; motor function; plasticity; neurodegeneration; subthalamic nucleus
Copyright © 2000 Society for Neuroscience 0270-6474/00/20134798-11$05.00/0